|About this Abstract
||Materials Science & Technology 2020
||Environmentally Assisted Cracking: Theory and Practice
||Elucidating the Loading Rate Dependence of Hydrogen Environment-assisted Cracking Behavior in Ti, Fe, Al, and Ni-based Structural Alloys
||Zachary D. Harris, Erin Dubas, James Burns
|On-Site Speaker (Planned)
||Zachary D. Harris
While literature indicates that the applied loading rate (dK/dt) can affect hydrogen environment-assisted cracking (HEAC) behavior, the quantification of dK/dt dependencies and mechanistic understanding of why the applied dK/dt influences HEAC remain limited. In this study, a slow-rising stress intensity (K) framework was utilized to measure HEAC kinetics over dK/dt ranging from 0.2 to 20 MPa√m/hr in Beta-C Ti, AA7075-T651, AA5456-H116, Monel K-500, and Custom 465-H900 stainless steel immersed in 0.6 M NaCl at applied potentials known to promote modest HEAC susceptibility. Results demonstrate that the crack growth rate (da/dt) exhibits two characteristics regimes of behavior with increasing dK/dt across multiple alloys. In particular, a ‘plateau’ regime where da/dt is independent of dK/dt was observed for elevated dK/dt, while a ‘linear’ regime where da/dt linearly scales with dK/dt was noted for slow dK/dt. The implications of these findings on recent testing standardization efforts for HEAC are then discussed.